Conventionally, a fishing spinning reel includes a rotor rotationally driven by rotational handle operation and a spool around which a fishing line is wound and which is reciprocated back and forth. As generally known, the rotor is fixed with a rotor nut on the front end of a pinion gear meshing with a drive gear mounted on a handle shaft and supported so as to be rotatable in a direction orthogonal to the handle shaft, such that the rotor is rotationally driven. The spool shaft is inserted through the pinion gear and reciprocated back and forth by an oscillation mechanism (reciprocation device) driven by the drive gear.
When the handle is rotationally operated to rotate the pinion gear, the spool shaft is reciprocated while being inserted through the rotating pinion gear; therefore, when the spool undergoes such a large load as to bend the spool shaft, the contact pressure between the inner surface of the pinion gear and the spool shaft is increased, resulting in increased slide resistance on the spool shaft and nonsmooth handle operation.
To overcome these problems, it is known to form a recess (gap) in the inner surface of the pinion gear along the axial direction to maintain a clearance between the inner surface of the pinion gear and the spool shaft, as disclosed in Japanese Patent Application Publication No. 2001-258438 (the “'438 Publication”). In the '438 Publication, the spool shaft is partially supported at regions except the recess. More specifically, the '438 Publication discloses a spinning reel wherein a spool shaft is supported at two points in the pinion gear ('438 Publication, FIGS. 5 and 6). Also disclosed in the '438 Publication is a spinning reel wherein a spool shaft is supported in the pinion gear at one point near the front end of the pinion gear and the spool shaft is supported by the reel body near the back of the pinion gear (id, FIG. 7).
The pinion gear is meshed with the drive gear to receive the rotational drive force. The pinion gear has teeth on the back side thereof and, at this portion (the meshing region meshing with the drive gear), the pinion gear is subjected to a large downward load (toward the spool shaft inserted) when the handle is rotationally operated to deliver the power. In the above related art, the spool shaft is supported at two points both within the pinion gear, or supported at two points one of which is on the front portion of the pinion gear and the other is on the reel body near the rear end of the pinion gear. Thus, the supporting portions supporting the spool shaft are relatively close to the meshing region between the drive gear and the pinion gear in the axial direction.
If such a supporting portion is in the meshing region, the downward load is applied directly to the supporting portion in the meshing region. The downward load produces frictional slide resistance on the outer circumferential surface of the spool shaft when reciprocating back and forth, which results in unfavorable nonsmooth handle operation. If the supporting portions are not in the meshing region and the spool shaft is supported at a portion near the rear end of the pinion gear (close to the tooth portion), when a downwardly urging load is applied to the pinion gear upon rotation of the handle, a force tends to bend the spool shaft via the supporting portion in front of the meshing region. This force radially deforms (into an ellipse) a bearing supporting the outer circumference of the spool shaft at the supporting portion near the rear end of the pinion gear, producing frictional slide resistance on the spool shaft reciprocating back and forth and resulting in nonsmooth handle operation. That is, supporting a spool shaft on the inner surface of the pinion gear in the meshing region or supporting the spool shaft on the reel body behind the pinion gear over a short distance across the meshing region may produce slide resistance on the spool shaft when a downward load is applied to the pinion gear in high load winding. This slide resistance negatively affects smooth rotational operation of the handle.